1. Field of the Invention:
The present invention relates to an image information transmitting and receiving system so designed that color information of an original picture obtained by analyzing the original picture into color components as image signals is modulated for example in amplitude or frequency and transmitted in a plane sequence, while at a receiving side the received image signals are stored in a memory.
2. Description of the Related Art:
FIG. 4 shows a conventional system of this kind. In the case of this system, an original picture such as a photograph is wound on a transmitting drum 1 which is driven by a motor 28. To a motor driver 27 for driving the motor 28, a signal, where frequency is divided by a frequency divider 26, is delivered from a crystal oscillator 6. By means of a rotation phase signal detected by a phase sensor 4 a carrier from a carrier generator 7 is modulated by a modulator 5, amplified by an image signal amplifier 10 and delivered to a transmission line 11. At this time, a signal delivered to the transmission line 11 is led to a monitor amplifier 12 to operate a monitor speaker 13.
On the other hand, at a receiving side the modulated signal is led to AGC (automatic, gain control) circuit 23 so as to adjust the output level, while the phase is detected by a phase detector 24 in the next step. A frequency divider 26 is reset by a synchronization signal produced by a phase synchronizer 25 so as to match the rotation phase of a motor 28 at the receiving side with that at the transmitting side.
Then a photoelectric converter 3 at the transmitting side is brought on the most white part of the picture, the carrier is modulated in amplitude or frequency by a modulator 8 by means of the signal photoelectrically converted at the point, amplified by the image signal amplifier 10 and then delivered to the transmission line 11.
When the signal is received at the receiving side, in order to detect and compensate the attenuation characteristics of the transmission line, the amplification degree of an ALS (automatic level sensor) 14 is set at a predetermined value by an ALS control unit 15 and a level comparator 17, while the gain is controlled so as to hold the set level until the image information for one picture has been transmitted. Then, at the transmitting side the photoelectric converter 3 is set at the beginning of the part to be sent out of the picture in such a manner that the electrical signal corresponding to the original picture obtained by successively moving the photoelectrical converter 3 for each rotation of the transmitting drum 1 is sent to the modulator 8, which delivers the modulation signal to be amplified by the image signal amplifier 10 and delivered to the transmission line 11.
When at the receiving side the signal from the transmitting side is received, the signal is adjusted in the level by the ALS 14, delivered to a demodulator 20 via a picture amplitude amplifier 18 and a remodulator 19 so as to be demodulated. This demodulated signal is non-linearly amplified by a gamma compensating portion 21 so as to be matched with the characteristics of the recording medium (in this case the film on the drum) and then amplified by a recording amplifier 22. When this amplified signal is led to a photoelectric converter 30, an image corresponding to this signal is recorded on a film on a receiving drum 29. This film is used to make the print plate.
At the time of the transmission of a color picture, color analyzing filters are provided in front of the photoelectric converter 3 in such a manner that information analyzed in colors by the filters transmitted as the signals corresponding to, for example, cyan, magenta and yellow, while at the receiving side the signals are recorded on the film on the receiving drum 29 for each color. Then, in order to obtain a color photograph, it is necessary to make a printing putting the films for each color thus obtained together. Consequently, by means of the conventional system it is impossible to evaluate the directly transmitted color picture on the spot and observe it on the monitor.
Thus, in order to evaluate the picture on the spot, a transmitting and receiving system by the MODEM transmission as is shown in FIG. 5 is known.
Below, the operation of the system shown in FIG. 5 will be explained. The image information inputted from a camera or scanner are analyzed into red, green and blue by the image input portion 30 and outputted as analog signals. These analog signals R, G and B are converted by an A/D converter 31 at sampling signal intervals from a sample pulse generating circuit 31' into digital signals, and stored in a frame memory 32 for each color information. The contents of the frame memory 32 are always delivered in a video rate to a D/A converter 33 so as to be converted into analog signals to be delivered to a monitor 34.
On the other hand, a central processing unit (CPU) 36 reads out the data for each color stored in the frame memory 32 via an interface 35 and carries out an operation processing. Then, the operation-processed data is modulated by a MODEM modulator 37, amplified by an amplifier 38, transmitted to the receiving side via a transmission line 39. The data received at the receiving side is demodulated by a MODEM demodulator 40 into digital signals to be delivered to a central processing unit (CPU) 42 in the next step. The CPU 42 controls an interface 43 in such a manner that the data for each color is stored in the corresponding R, G and B memories in a frame memory 44. Then, the stored data is always converted by a D/A converter 45 into analog video signals to be delivered to a monitor 46.
As explained above, in the case of the MODEM transmission shown in FIG. 5, it is easy to position the display of the received image for each color by the monitor 46, and the color deviation as is shown in FIG. 6 can be avoided.
On the other hand, in the case of the system as is shown in FIG. 5, in order to carry out the MODEM transmission it is impossible to receive the signals transmitted from the system shown in FIG. 4 and modulated in amplitude or frequency and monitor or to transmit and receive the signals for making the print plate for each color. Namely, the system shown in FIG. 5 is not interchangeable with the system shown in FIG. 4.